Apparatus and method for control, pumping and abatement for vacuum process chambers
View Patent ↗The present invention is an apparatus and method for controlling pressure, pumping a vacuum and providing abatement for a plurality of vacuum processing chambers. The system may be used in semiconductor manufacture. Multiple vacuum processing chambers are exhausted by turbo pumps into a common abatement chamber, which is maintained at sub-atmospheric pressure by a backing pump. Pressure in the processing chambers is independently controlled. The internal volume of the abatement device provides a buffer that reduces the effect of pressure changes in one processing chamber affecting pressure in the other chambers.
1. A vacuum exhaust apparatus for exhausting gas from at least two process vacuum chambers, comprising:
a sub-atmospheric chamber having at least two inlets and an outlet and having a sub-atmospheric abatement device for conditioning exhaust;
a plurality of high-vacuum pumps, each said high-vacuum pump connected on an exhaust side to one of the inlets of the sub-atmospheric chamber, each said high-vacuum pump being connected on a vacuum side to one of the process vacuum chambers for controlling vacuum within that chamber; and
a backing pump connected to the outlet of the sub-atmospheric chamber, for maintaining vacuum within that chamber.
2. The vacuum exhaust apparatus of claim 1 , wherein the sub-atmospheric abatement device is a scrubber.
3. The vacuum exhaust apparatus of claim 1 , wherein the sub-atmospheric abatement device is a plasma device.
4. The vacuum exhaust apparatus of claim 1 , wherein the sub-atmospheric chamber is proximate the process chambers.
5. The vacuum exhaust apparatus of claim 1 , wherein the sub-atmospheric chamber is remote from the process chambers.
6. The vacuum exhaust apparatus of claim 1 , wherein an internal volume of the sub-atmospheric chamber reduces an effect of pressure changes in one of the process chambers on pressure in another of the process chambers.
7. The vacuum exhaust apparatus of claim 1 , wherein the high-vacuum pumps are turbo pumps.
8. The vacuum exhaust apparatus of claim 1 , wherein the high-vacuum pumps are turbo pumps capable of exhausting to a pressure of over 1 torr.
9. The vacuum exhaust apparatus of claim 1 , wherein the high-vacuum pumps are turbo pumps capable of exhausting to a pressure of over 5 torr.
10. The vacuum exhaust apparatus of claim 1 , further comprising throttle valves connected to exhaust sides of the high-vacuum pumps.
11. The vacuum exhaust apparatus of claim 10 , wherein the high-vacuum pumps are turbo pumps.
12. The vacuum exhaust apparatus of claim 1 , wherein the backing pump is proximate the sub-atmospheric chamber.
13. The vacuum exhaust apparatus of claim 1 , further comprising an atmospheric abatement device connected to an exhaust side of the backing pump.
14. The vacuum exhaust apparatus of claim 13 , wherein the atmospheric abatement device is a device selected from the group consisting of a wet scrubber, a dry scrubber and a combination dry/wet scrubber.
15. The vacuum exhaust apparatus of claim 1 , comprising four process vacuum chambers and four high-vacuum pumps.
16. A semiconductor manufacturing system, comprising:
a plurality of semiconductor vacuum processing chambers;
a plurality of pressure control units, each said pressure control unit connected to one processing chamber for evacuating said chamber;
a single sub-atmospheric abatement chamber connected to exhaust sides of each of said pressure control units, whereby all of said pressure control units exhaust into the single sub-atmospheric abatement chamber;
abatement means in the sub-atmospheric abatement chamber for conditioning exhaust in the sub-atmospheric abatement chamber;
a single backing pump connected to the sub-atmospheric abatement chamber for maintaining sub-atmospheric pressure in the sub-atmospheric abatement chamber; and
an atmospheric abatement chamber connected to an exhaust of the backing pump.
17. The semiconductor manufacturing system of claim 16 , wherein said pressure control unit comprises a turbo pump connected for evacuating the one processing chamber, and a throttle valve connected to an exhaust side of the turbo pump.
18. The semiconductor manufacturing system of claim 16 , wherein the abatement means in the sub-atmospheric abatement chamber is a plasma device.
19. The semiconductor manufacturing system of claim 16 , wherein each of the plurality of pressure control units is connected directly to the sub-atmospheric abatement chamber.
20. The semiconductor manufacturing system of claim 16 , wherein each of the plurality of pressure control units is connected remotely to the sub-atmospheric abatement chamber.
21. The semiconductor manufacturing system of claim 16 , wherein each of the vacuum processing chambers is located within a clean room, and the sub-atmospheric abatement chamber is located outside the clean room.
22. The semiconductor manufacturing system of claim 16 , wherein an internal volume of the sub-atmospheric chamber reduces an effect of pressure changes in one of the processing chambers on pressure in another of the processing chambers.
23. A method for exhausting gas from a plurality of process vacuum chambers to achieve a process vacuum pressure, the method comprising the steps of:
evacuating to an intermediate vacuum pressure greater than the process vacuum pressure, the process vacuum chambers and a sub-atmospheric abatement chamber, using a backing pump connected to an outlet of the abatement chamber;
independently evacuating to the process vacuum pressure each of the process vacuum chambers using a plurality of high-vacuum pumps, each of said high-vacuum pumps being connected for evacuating one of the process vacuum chambers;
each of said high-vacuum pumps further being connected for exhausting into inlets of said sub-atmospheric abatement chamber; and
conditioning exhaust in the sub-atmospheric abatement chamber using an abatement device.
24. The method of claim 23 , further comprising the step of independently controlling a pressure in each said process vacuum chamber using a corresponding high-vacuum pump and a corresponding throttle valve at an exhaust side of each high-vacuum pump.
25. The method of claim 23 , wherein the intermediate vacuum pressure is between 5and 10 torr.